Transmission devices or phase shifter gearboxes of this type are used to shift torque between the wheels of an axle in motor vehicles. To this end, in addition to the actual differential, corresponding devices or phase shifter units are provided where, for each transmission direction, a multi-disc clutch is provided.
From the Applicant's DE 103 48 959 A1, a transmission device is known for distributing drive torque to at least two output shafts and having at least two planetary gearsets with at least three shafts, where the planetary gearsets serve as differentials. Here, in each case, a shaft of a planetary gearset is connected to an input shaft, and a second shaft of a planetary gearset is connected to one of the output shafts. Furthermore, in each case, a third shaft of the planetary gearsets is functionally connected to a brake such that a degree of distribution of the drive torque, between the two output shafts, varies as a function of the transmission capacities of the brakes. DE 103 48 959 A1 additionally describes a method of controlling and regulating the known transmission device in which, to distribute a drive torque of a drive unit between the two output shafts of the transmission device, the transmission capacities of the two brakes are adjusted such that one brake has a synchronous state and the transmission capacity of the other brake is varied between a lower threshold value and an upper threshold value that corresponds to an engaged state of the brakes.
The Applicant's DE 103 48 960 A1 also describes a transmission device for distributing a drive torque to at least two output shafts having at least two planetary gearsets with at least three shafts, where the planetary gearsets serve as differentials and, in each case, a shaft of a planetary gearset is connected to a drive shaft. Furthermore, in each case, a shaft of a planetary gearset represents one of the output shafts where, in each case, at least one additional shaft of a planetary gearset has a functional connection to a shaft of an additional planetary gearset. A torque of a shaft that depends on the operating state, subject in each case to an operating state of the other shaft that is functionally connected thereto, can be supported via the functional connection such that when a difference in the rotational speeds between the output shafts occurs, a torque that changes the rotational speed difference is applied to the planetary gearsets by way of the functional connection.
The German published patent application 2 017 716 describes a steering gear for tracked vehicles, in particular for snow cats, comprising a drive pinion, a ring gear that meshes therewith and is fixedly connected to an inner transmission housing, as well as compensating gears rotatably supported inside the housing and at least two output shafts. A second differential gear is thereby superimposed on this known differential gear, where one or the other side of the superimposed differential can be completely or partially immobilized.
In addition, a differential gear is known from DE 697 10 033 T2, comprising a rotatable component on the input side for receiving an external drive force, two rotatable components on the output side that are arranged co-axially to the axis of rotation of the rotatable component on the input side; a transmission housing in which the input-side component and the output-side components are supported in a freely rotatable manner, where a torsional force of the input-side rotatable component is transmitted to the output-side rotatable component, while a different rotational speed is allowed between the output-side rotatable components.
In addition, this differential gear comprises a first input-side, gearwheel that is provided on the input-side, rotatable component at an axial end thereof, the component being rotatable together with the input-side, rotatable component; a second input-side, gear wheel that is provided on the input-side, rotatable component and can be rotated together therewith; a first output-side, gear wheel having a deceleration ratio that is greater or smaller in relation to the first input-side, gear wheel, where the first output-side, gear wheel can be rotated together with the output-side, rotatable components; a second output-side, gear wheel having a deceleration ratio that is smaller or greater in relation to the second input-side gear wheel; at least one planetary gear that meshes with the first input-side, gear wheel and the first output-side, gear wheel and at least one second planetary gear that meshes with the second input-side, gearwheel and the second output-side, gear wheel.
In the transmission according to DE 697 10 033 T2, the second input-side, gear wheel is arranged on the input-side, rotatable component at an axial end thereof where the second output-side, gear wheel can be co-axially rotated with one of the output-side, rotatable components. In addition, the differential gear comprises a carrier that supports the first planetary gear and the second planetary gear, such that they can rotate around their own axes and rotate around the axis of rotation of the input-side, rotatable component.
In addition, a first rotation control is provided for controlling the rotation of the carrier about the axis of rotation of the input-side, rotatable component with arbitrary control force and a second rotation control for controlling the rotation of the second output-side, gear wheel with arbitrary control force, where the rotation controls comprise a plurality of friction plates, which can be rotated together with the carrier or the second output-side, gear wheel, as well as a plurality of friction plates that can be rotated together with the housing. Furthermore, pressure media are provided for compressing the friction plates with an arbitrary compressive force. This known transmission disadvantageously comprises a large number of components and the manufacturing and installation costs are high.
The present invention is based on the aim of providing a transmission device for distributing a drive torque to at least two output shafts, comprising a differential that has a simple design. In particular, the phase shifter unit shall be integrated into a differential, where the actuation of the phase shifter unit on one side of the differential shall be enabled.